Intranasal immunization with formalin-inactivated virus vaccine induces a broad spectrum of heterosubtypic immunity against influenza virus infection in mice

Cytotoxic T cell vaccination with PLGA microspheres interferes with influenza A virus replication in the lung and suppresses the infectious disease

“…This heterosubtypic immunity is generally mediated by cytotoxic T lymphocytes (CTLs) [7]. It was demonstrated before, that patients with measurable T cell responses were able to clear the virus effectively, even though they lack anti influenza virus specific antibodies for the particular influenza virus subtype [8].…”

“…Current vaccines induce serum neutralizing antibodies but only little local immune response after parenteral immunization with inactivated virus. Intranasal immu nization on the other hand was shown to be able to stimulate mucosal immunity and CTL responses, which serve as a first line immune defense by suppressing initial viral replication in the respiratory epitheli um [7,11,12]. Nguyen et al could show that mice immunized with a live nonpathogenic influenza virus strain via the pulmonary route survived challenge with a pathogenic influenza strain in contrast to mice that were immunized intravenously or intraperitoneally, which showed only minor protection [13].…”

Intranasal Inactivated Influenza Vaccines: a Reasonable Approach to Improve the Efficacy of Influenza Vaccine?

“…Enhancement of specific Ab responses by whole inactivated virus vaccines Intranasal immunization of mice with formalin-inactivated WV vaccines, but not SV vaccines, induces a broad spectrum of heterosubtypic immunity against influenza A virus infection in mice (68). The effects of adjuvants on nasal anti-HA S-IgA and IgG Ab responses induced by SV or WV vaccines derived from A/New Caledonia/20/99 (H1N1) viruses were compared in BALB/c mice that received primary and secondary intranasal administrations with 0.1 mg of SV vaccine alone, 0.1 mg of SV vaccine plus CTB * , 0.1 mg of WV vaccine alone, or 0.1 mg of WV vaccine plus CTB* with an interval of 3 weeks (62).…”

Phase I Evaluation of Intranasal Trivalent Inactivated Influenza Vaccine with Nontoxigenic Escherichia coli Enterotoxin and Novel Biovector as Mucosal Adjuvants, Using Adult Volunteers

“…While current intramuscular influenza vaccines are effective at inducing immunoglobulin G (IgG) for serum hemagglutination inhibition (HAI), they are poor at stimulating mucosal secretory IgA (8,22,32). Mucosal IgA exhibits both heterosubtypic cross-reactivity to influenza virus strains and potent immunological memory (10,37), properties that offer potentially wider protection against variants of influenza virus that have drifted antigenically from the vaccine strain (33,34). Thus, stimulation of both local and systemic immune responses following influenza vaccination may enhance vaccine efficacy, particularly among the elderly, who exhibit age-related reductions in immunity to vaccination.…”